According to Frlec et al.,[1] theoretical studies indicated that there is a possibility (albeit slim) that neutral xenon octafluoride ($\ce{XeF8}$) might exist.

I am curious as to what structure this molecule might possibly have. In terms of hybridisation theory, I have only learnt cases up to seven-coordination ($\mathrm{d^3sp^3}$ or $\mathrm{sp^3d^3}$), where the molecular geometry is pentagonal bipyramidal. However, answers based on other frameworks (e.g. molecular orbital theory) would also be welcome.